Ethylene glycol (c2h4(oh)2) , when dissolved in water, provides the standard ‘anti-freeze’ coolant for water-cooled engines. in order to depress the freezing point of water by 20 °c, how many grams of ethylene glycol would need to be dissolved in 15 kg of pure water? (the molal freezing point depression constant for water kf = 1.86 k mol-1 kg and the relevant atomic masses are: c = 12g, h = 1g and o = 16g.) note: ethylene glycol is an organic compound and does not break up or dissociate when it dissolves in water. hint: first calculate the molality (m) of the ethylene glycol solution.

what is the boiling point of this same solution at atmospheric pressure? (the molal boiling point elevation constant for water kb = 0.52 k mol -1 kg.)

146,575 grams of ethylene glycol would need to be dissolved in 15 kg of pure water

The boiling point of the solution is 181.95°C.

Explanation:

Mass of ethylene glycol = x

Molar mass of ethylene glycol = 2 × 12 g/mol + 2 × 32 g/mol+ 4 × 1= 62g/mol

Moles of ethylene glycol =

Mass of solvent that is water = 15 kg

The molal freezing point depression constant for water

Molality of the solution:

Depression in freezing point of water =

((T)°C =T+ 273.15 K)

x = 146,575 g

Boiling point of this solution =

The molal boiling point elevation constant for water

Normal boiling point of water is = T = 373.15 K

The boiling point of the solution is 181.95°C.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.